Conventional transmission control circuits for the control of a system pressure in a transmission control the system pressure to a predefined constant pressure level. The pressure level is selected to be sufficiently high that the hydraulically operated clutches and brakes within the transmission can transfer torque without slip even under high load. This design achieves a high capability of torque transfer capacity on the one hand, but takes into account that the pressure pump provides the high pressure level continuously, even if this would sometimes not be necessary for the reliable transfer of torque. From the viewpoints of efficiency and consumption, it would be desirable to deliberately relieve the load on the pressure pump if a reduced system pressure would be sufficient for reliable torque transfer. In particular, it would be desirable to variably adapt a reduced system pressure to currently existing operating conditions of the working machine.